Improvement in gages for machine-drills



2 Sheets-Shefet T.

` E. G; PARKH u RST. lmprvement in Gagesfor Machine-DHHS.L

Patented 0ct.1, 1872.

No.A 131,775.

UNITED STATES PATENT -OFEICE EDWARD e.. PARKEuRsnoE HARTFORD, ooNNEoTIoUnAssIGNeR To EIM- sELEAND THE PRATT a WHITNEY COMPANY, .OE sAME PLAGE.

IMPROVEMENT IN GGES FOR MACHINE-DRILLS.

Specification forming part of Letters Patent No. 131,775, dated October 1, 1872.

To all whom it may concern:

Be it known that I, EDWARD G. PARKHURsT, of Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in MachineDrills 5 and I do hereby declare that the following is a full,

clear, and exact` description thereof, whereby a person skilled in the art can make and use the saine, reference being had to the accompanying drawing and to the letters of reference marked thereon. y

Like letters in the gures indicate the same parts.

vice for registering the distance the drill "penetrates from any given position, and showing at a glance the number' of inches and fractions that the drill has bored into the' work. The object of my invention is to measure withv accuracy the depth of the hole drilled without removing the drill or measuring with any detached instrument the distance any part of the machine has traversed. i

In the accompanying dra 'ng on two sheets, Figure 1 is a side view of partof a machinedrill having my invention applied; Fig. 2 is a top view ofthe same, `showing, more particularly the zero-point and measures upon the indexwheel5 and Fig. 3 is a -front view of the same. 1

. A is part of the frame of the machine. B is the sliding sleeve which carries the revolving drill-bar up and down. The drill-bar revolves in the circular opening in the middle of B, and has a collar above and` below, so that its motion up and down is controlled by ,the sleeve. C is a rack, which works in a pinion upon the shaft .fr y, which passes through they frame of the machine. D is a wheel furnished with a handle, H, for turning the shaft or arbor a' y. E is a fixed circular part of the frame A, having a circumference concentric `with the arbor a* y. F is a circular disk, run- My invention consistsin an adjustable de-` 'the usual manner.

loosening it, as desired. When clamped to the -deiinite movement downward ofthe sleeve B for instance, the turning of F through one division, from 0 to l of the graduations, would .move the sleeve downward one inch. In the drawing thegraduations are in inches and fractions, as commonly used, but any other units can be used. The zero-point is placed on the fixed disk E, and the graduations on the movable wheel F, but these can be reversed,if desired. A few divisions, from 0 to g., by sixty-fourths of an inch, are 'shown in Fig, 2. These measure by the 0 on F passing along them the same as the 0 of E passing over the divisions of F.

.The operation of my invention is as follows: When the work to be bored is placed under the drill the drill-bar is lowered by means of `the wheel D and handle H until the point of the drill touches the work. The nut G is then loosened and the two zero-points set together. The drill is now revolved and fed downward by any usual method. As it descends the wheel F, being clamped to the same arbor as the pinion running in the rack C, revolves, and the divisions opposite the 0 on E show, in inches and fractions, the exact depth from the starting-point the drill has reached.

It will be observed that, by means of my invention, a hole can be drilled of an exact depth by inspection, with ease and certainty, and' without taking any measurements by hand in It-Will also be observed that whatever be the position of the drill at starting the two zero-points of the wheel F and the circle E can be brought to coincide by loosening the nut Gr and again clamping it after setting the wheel. 'I he measurement on the wheel then becomes positive and direct without any additions or subtractions on the scale.

In the foregoing description of my invention the devices E and F are both represented as complete circles. In some cases, however, it may be With a Vernier for measuring minute divisions,

if desired.

Claim.

What I claim as my invention is The circle E, Xed to the frame of a machinedrill, in combination With an adjustable index- Wheel or its equivalent and a clamping device for measuring the distance moved, substantially as described.

E. G. PARKHURST. Witnesses:

THEO. G. ELLIS, FRANCIS A. PRATT. 

